| 摘要 |
PROBLEM TO BE SOLVED: To suppress a breakage of a coupling part of an arm having a step at a tip thereof and a rotary support shaft.SOLUTION: A step plate 3, which is rotationally displaced between in a used state in which the step plate is projected to a side part of a vehicle body and a non-used state in which the step plate is stored in a lower part of the vehicle body, is attached to a tip 15a of a rotary arm 15. A base end part 15b of the rotary arm 15 is coupled and fixed to a body side rotary support shaft 23. The body side rotary support shaft 23 is rotatably supported on a bush 37 of a body part 13 fixed to a vehicle body side. A lower part of the body side rotary support shaft 23 is coupled and fixed to a lower part of a mounting hole 53a of the rotary arm 15 via a weld part 55. The weld part 55 has an inclined combination plane combined with a core 53 for shaft fitting on an outer peripheral side. A corner part R inside of an upper part of the bush 37 is positioned on an extended line Q of the inclined combination plane. When the rotary arm 15 receives a load applied to the step plate 3, a moment is generated around the corner part R as a center, and a reaction force thereof perpendicularly acts on the inclined combination plane. |
